Image forming apparatus including recording head and head tank

Abstract

An image forming apparatus includes an apparatus body, a recording head, a head tank, a carriage, a main tank, a liquid feed device, a supply controller, a displacement member, a first detector, and a second detector. When a consumption amount of liquid in the head tank reaches a threshold value, the controller controls the feed device to start supplying the liquid from the main tank to the head tank. When printing operation is not performed and the displacement member is at a position at which a remaining amount of the liquid in the head tank is smaller than when the displacement member is at a first position, the controller controls the feed device to supply the liquid until the displacement member is placed at the first position or a position at which the remaining amount of the liquid is greater than when the displacement member is at the first position.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]This patent application is based on and claims priority pursuant to 35 U.S.C. §119 to Japanese Patent Application No. 2011-268585, filed on Dec. 8, 2011, in the Japan Patent Office, the entire disclosure of which is hereby incorporated by reference herein.BACKGROUND[0002]1. Technical Field[0003]This disclosure relates to an image forming apparatus, and more specifically to an image forming apparatus including a recording head for ejecting liquid droplets and a head tank for supplying liquid to the recording head.[0004]2. Description of the Related Art[0005]Image forming apparatuses are used as printers, facsimile machines, copiers, plotters, or multi-functional devices having two or more of the foregoing capabilities. As one type of image forming apparatus employing a liquid-ejection recording method, an inkjet recording apparatus is known that uses a recording head (liquid ejection head or liquid-droplet ejection head) for ejecting dropl...

AI Technical Summary

Benefits of technology

This solution stabilizes print quality by maintaining optimal liquid levels and pressure in the head tank, preventing excessive negative pressure and liquid leakage, and ensuring reliable nozzle operation during resumed printing.

Problems solved by technology

If the next printing operation is performed from the actual position differing from the assumed position until the third position is detected, an excessive negative pressure in the head tank may cause degraded print quality or air sucked into nozzles may cause ejection failure.

In addition, when the displacement member is at a position at which the remaining amount of liquid in the head tank is greater than when the displacement member is at the first position, an excessive amount of liquid may be supplied, thus causing liquid leakage from nozzles.

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